Rod reduction assemblies and related methods

Abstract

This disclosure describes example embodiments of rod reduction instrumentation and other rod and vertebrae manipulation instruments. The rod reducers can be used during the installation of a rod based surgical fixation system to help urge the rod into the fixation anchors. The reducers described provide various configurations delivering large reduction distance capabilities, strong controlled reduction coupled with an ability to quickly advance the reducer if desired, and reduction of bulk through the surgical corridor.

What is claimed is: 
     
         1 . A system to facilitate seating of a spinal rod into a rod-receiving portion of a fixation anchor, comprising:
 a rod reducer having a coupling unit and a translation unit, the coupling unit including a pair of anchor coupling arms situated at a distal end of the coupling unit, the anchor coupling arms each including an engagement feature that engages complementary engagement features on the rod receiving portion of the fixation anchor and a locking mechanism operable to inhibit disengagement of   the coupling arm engagement features from the complementary engagement features on the rod receiving portion of the fixation anchor, the coupling arms being spaced apart to define a cavity and a rod channel therebetween, the translation unit including a distal rod engagement end that advances in a distal direction relative to the coupling arms, the distal rod engagement end being coupled to a translating mechanism that drives the distal advancement of the distal rod engagement end,   
       wherein the distal rod engagement end advances through a lumen in the coupling unit 
       wherein the locking mechanism is biased to an unlocked position. 
     
     
         2 . The system of  claim 1 , wherein the locking mechanism and the translation mechanism are unconnected. 
     
     
         3 . The system of  claim 2 , wherein the locking mechanism is a cam-over mechanism. 
     
     
         4 . The system of  claim 2 , wherein the locking mechanism includes a locking bar coupled to a locking lever, and wherein rotating the lever causes the locking bar to move across a cam surface. 
     
     
         5 . The system of  claim 3 , wherein the cam surface includes a pair of grooves separated by a lip. 
     
     
         6 . The system of  claim 1 , wherein the locking mechanism and the translation mechanism are connected. 
     
     
         7 . The system of  claim 6 , wherein the translation mechanism includes handles having distal ends rigidly coupled to the coupling unit and proximal ends coupled to the translating unit by a translation link. 
     
     
         8 . The system of  claim 6 , wherein operating the translation mechanism includes flexing the proximal ends of the handles towards the translating unit. 
     
     
         9 . The system of  claim 1 , further including an anchor clip, the anchor clip having coupling arms each including an engagement features that engages complementary engagement features on a rod receiving portion of an additional fixation anchor and a locking mechanism operable to inhibit disengagement of the coupling arm engagement features from the complementary engagement features on the rod receiving portion of the fixation anchor. 
     
     
         10 . The system of  claim 9 , wherein the anchor clip has no reduction capabilities. 
     
     
         11 . The system of  claim 10 , wherein the coupling arms of the anchor clip define a rod slot that is wider than the diameter of the anchor housing. 
     
     
         12 . The system of  claim 11 , including at least one additional rod reducer and at least one additional anchor clip.